SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '96b7708e37ecc25a62a83c34344816184f17f67deb4985796c74c75005f2176c' 
  AND token = '6HAru96Zdru6pJum9z72YwalO3/EKKPqypxHNBFY/us=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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