SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '95d74cfb58ffe71cc5492f5fc802212802be0b358cf3b802c45cfc4f31db6bef' 
  AND token = 'MHtYwzD8lbAcKCKfhcepO7QsOOV940T+bezKcDRYyHE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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