SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd4846d675437a7554ccf9c74ee76829500f4766ba46097f6ab8cade69ad4aae2' 
  AND token = 'qmjGS1UtDiXkUTzZVjZxJoA+1uNRbnPg2YnQWljANGw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00101

JSON explain

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