SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b25b1efa7861f5a98f4fa1604e26cc13fab7802f369be1406a3ad1d7e760cac0' 
  AND token = 'rYznerpTtCJwlxh3aWYS5Gkb+D6jw+m0aYdKoHNY26w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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