SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a498ad903c976ff7751b480d5eae7ec940430a40fd6b2bcd65e6e657eae54a2' 
  AND token = 'ojPsR4CDvhUfUcQniKeuZTHv3xhPZuhhtjhyYQ56By4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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