SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3602299e21e4c8863f2ebd315d01ea1b4c7138c97448095008e29afd7c700f3d' 
  AND token = 'tPrZJq5+117VCBSifLRLV/3JK8vFgrXY99tnDohgIls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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