SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '78cdfe5124f215014fbc9c51a2905a19ef9a05bb7adfb5e4812d92860142a3a4' 
  AND token = 'jT63j915A2OMubxt1KBjAB+JZpyVnpipeFYr3k19PRA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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