SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ab67668a9462c3aa594849f0312007f651a9eb815732064d6981c4646ae8441' 
  AND token = 'gI5tQYIm7PkDP1b2SkYJ0JPiEPPBDECkoWQAEciJ06I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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