SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b1ef8667fbd6315bd5f1623194cc9e815435f8ebf98d1e8eae4cc43f154d3965' 
  AND token = 'q6GIaLhQHXy+0ZbmhgzpLiM0XUL8g1PDER1QHtcneEs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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