SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7c984bae2146b70b734a782b02df3eca372a4ed0c8c7dbfad560fc3682ee805' 
  AND token = 'Jg+70Ua5DB5PncexDjZ5a16JdGlTKjyciZfoOq7YPYE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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