SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a2962e05c734779bd29808c66a14cb185241c523836036db2041f9a18469327' 
  AND token = 'u3lsoUnW4GKF6qn3PyNhE7efWGTszZJ8CzIKdp37be8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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