SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'be7558bd843bf75664b2cc8f199883d4ff5b83da59bd39c46d34320cb8bc273b' 
  AND token = '5l1NYXZVlBveDCtl+XFk5h3xMF0cRzMPtIXFYEoW+sQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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