SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcb488024ff68725dc5995d0ff27dce9b5804bd27b057494dec9588572914a72' 
  AND token = 'L7qfvA55gl/AQkwMMBHOy2nNLDlqD5LTOEI0gfXRDmY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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