SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '37b4c1b67b65f9e922b101552ed75485cefcb29599627455a1083e93eb95c7f3' 
  AND token = 'Eg+rA9oZ519fZFW8fH/78RMa8UQWk0yMp2loZoguIdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}