Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15204f2a4d2b1abb9945cfed3e2ce35b2eee48bbf6ef8be5969f68d53b4d94ea' 
  AND token = 'vr7+/5mM39qpJlgUp5aDfE2dWM43aTVQXn2y1YQrMCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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