SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd39b4f4c87b1a22091ac16485ca7698aa1dddfc84db1945bfda73145a6a36920' 
  AND token = 'XwMcU0JsX7/EvataJMFTZFeiL184aZUFCfKpESf8c9g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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