SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0b99e219f6aa45228b5da4324e71a83efaf57f0a8752d39e03ec85a5b26ed640' 
  AND token = 'pP0JGKPwb0Yp5QgYd/rMl4HojYyEnhepQjpceogE+rQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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