SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cad080292f524ed014efa35b2d0d32ed524786e3560a3c830968997082e0f6b9' 
  AND token = '3jFpHgUGwA7tkDDtf8zPSdMPv6ryqBTRWW2agLoCOn4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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