SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f34f24e0bea1c3a607b047b79b73f7062b67267b3c21013accdfb757badf9fc' 
  AND token = 'PLkBBgpEcT8qEsor5Ah7EEEgbY6nnZSXdkoqROdnyps=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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