SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f29831c8f8f9259623d905146d74615914394d9c52d01ac36401fabafd034f48' 
  AND token = 'iSASEuFKCkj/QEceMjCD4sopln1vF4zmVXze5vZVg4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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