SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b914575e21ef09daab0ce1393fbf3c62f56ce93f11ca69205ff69eb25991092' 
  AND token = 'y1TEQ8Eoq4xrGnJb/dmx4G8o3noZIpocfH4v8JST0Yo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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