SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ee6653d520e5ab2d51bef37f215692aee8eb96cab61e485571475a957daf512e' 
  AND token = 'ZP7KTBCx8WEy2+nPOu+mhYlnYlW/DOzHIvvSxOE4sHI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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