SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a1ae10a45d4d183585547e07bf89eb943b92f117fef18ea1debdd508271aebb' 
  AND token = 'F3HXMCV5aMkHPSKymCewES1oDrVTqoKIvTVfaAYNVR8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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