SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0f81191af1a7eca56b3d8a0a9904adcdea4266e3f3d96dc6ef1ddb193d8042a4' 
  AND token = 'zaDNQxJ+UwepmQphWdiP+o77APsDqdHNM9Y09LKMvDE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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