SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '216488f137dd968544927ff31fac87517fa1acd182f0d99a84404a143848324f' 
  AND token = 'zVf47QcCkehz9JmIo+DtQW8YLxkfHb1S0HQ8/LpHN5w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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