SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '025087fe6c62ee1c5cefb465c21e8017909f5b60b0e09a05d0451bc8698c06ca' 
  AND token = '6ON7ZjsHJBzJI+TvbgQxDKXQvhNHzEAOtdbUnxMF03Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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