SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8f398d4405cd3b14db4ece001fbcfa22af66bce48643f6aa96354f282c705ead' 
  AND token = 'kKbCwBhoh5hMw5uZMsT0N6Hmn3KOFGTTD82Nicq5RTc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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