SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '87381509b458f4ff59f3094b8f3995aa98b02b7c51e0b20c3fc99e0a8ab2a8f8' 
  AND token = 'uwgSrAC2CuP5f0MemYpJPGVZoLwnjY4zNz85L6phny4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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