SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '17fc6bb6046b592774fd264b5c8bccbd4db54932c46ff25a27ececf619db145f' 
  AND token = 'hRqnJsK8ucD2FjXbcGJkXRCkSmPzsUpscjOjfC9BK3w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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