SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3b1f431ae4a97e7db6d6b87ecbcc8c1a4db2264ca5719424a87d3893fc69b2d0' 
  AND token = 'qsMGZGJu/zoew7OTRxT8zCCG06J3UkhfbBOFBN+DRQI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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