SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7f1a19bb8ab2afb8a202ff809da7d925c508144d92490294bf30f47739ec414f' 
  AND token = 'WmSSInJpGXRs8CTZS/kGTbSmhsAvgoXG1EyxJ52lJu8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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