SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4d2de3559f631b2483598775371264a2cbd5185033079cd6dc6d59f29d72d6f0' 
  AND token = 'Kch/umAFMBlCnusQuJBZPwTrTBpoVIaAgHTjZTpQkg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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