SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fac85f7f90605b2ffff8afba037635b50c16b123d612ec8adbaefcef6bedd920' 
  AND token = 'ahvf3uyIvW314zSQWmspWZrIj+osYjEKo4+LLmGXrA8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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