SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a93d57c5f58e4940ceba6cd4823cae588d7a435c90679a9ea02b11d6dc0cef3' 
  AND token = 'm+FYS5bCocMubywsKyI/OmLeFIxY/6tY8X9EpQqPUU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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