SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98cd9ada128e398f7490eab84461054d1eda889eafd6d2d72ce99d5a513d7828' 
  AND token = 'GkApSCIi9LHGviiTh6DUFIJ1vchG4cf102CDNr9ute4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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