SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abf270bb09eefa9bcd59dccb4db1bceb53f845e1c0f76949a1aa7bfdbdf5caf0' 
  AND token = 'hnkBRejN8wW64eT7Aqk4sLptDOkCetzLukUfXSvHvA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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