SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9bfd830a1acc53b03035f4cb0756bb3b136dc17bba2823128d1150b37857e171' 
  AND token = 'MSEnHNBq1Yx3psITMAqwJr+rib2iQNyWdZBVHMcm0/w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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