SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '281a8809fbb65cdf50cd0ba03344f841e17bb8febf0316acfd0acc4d81410638' 
  AND token = 'PRdZCbgEvLNGJLXHyljLQLuOC0XvEKTQc8ND2Et72lQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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