SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42699f3fa8db502a033328cc7642700f03f5214c6ca924772efd2b010786c039' 
  AND token = 'wFrwkVWqrEzbb9LaQV3NVFWH6pWW0Ang08GGPfyyEH0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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