SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3f49be536d57f055f4e5f0e09c18f3de66c58bf0bf289ab4cadfe4bf283188f' 
  AND token = '0D521r+QQD+QbxyG8aA+kI+UKVgZY8lUBs+hLXi7Bqo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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