SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e3fe157530bb8ea522e45a26264b71993d5372df90489f58bf918b72a892bedf' 
  AND token = 'KU3/p3qN70p2mVKXuisswB8SRrMnSQgioNfG1Oa0PAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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