SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd9c20f9a52c8b5da3e28168961ac49b9dcf47982317b92673056d0701452d8a0' 
  AND token = '7MDwB6ls+s2V4gXVGkTloejlCYJ1S5NWeeDt+v32ktg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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