SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2037e5dfd312bb39661672044dcb8a2f5f7fd2f14cf28ee99993c8bb0107e5d' 
  AND token = 'PhtP18oSMKaAWQpJegYXH05+7u4zu49TAZ01PwDjk5g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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