SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '461cf818f8739e30956fdbcce4bd65d5ec1b2c8524dcd26f117e32bcde45e418' 
  AND token = 'Mmobe//WqDexron7xlBqRrUkA9SgkVavzS/abgLAvo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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