SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad43a40779df94b20c858b1367aaef35397b034df55cc80e816e9608908ca20a' 
  AND token = 'zJp+CfkeB1aGxY6ySxeNqMTr25Fpc9+2JCrCL8y7gK0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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