SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98c0379bda36b15e33f5c2e36f26ab85a2756e49053e64d633998eb8f93bd874' 
  AND token = '/Ozt4EhuZ/YvfFDS0Z+ils+WXJTZFOLswW9kNxZccx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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