SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d55cde347a05e0dbc0bb0b32423b7ab347af7c67dfaba85641ab0cab5296bd9' 
  AND token = 'r69l65jCd55aIIt/2JA8m8EH/NnIwY9xxpdF2z8c4JQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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