SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0618da019bd3a49dec86e3aea7d781c4f43652c82f477ab85a4a93432a99ad23' 
  AND token = 'FyyaEpoYsjoD+joxWUEZiYqGXKPs1rZZFvkQjg/JhSA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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