SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '65560d76af138e845ac0b2abda9c385a19ab8928a597be2a9f472c74234465a4' 
  AND token = 'Ob6it0PiLNgmAii7d9ngBbRU2SpUFeE4fsOMGqy81Kw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}