SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '15b1aea919248417e79f7432cf6b1ea79763d8cc2162fa79536066ce7f9b4b04' 
  AND token = '7agWQy+wh2Sr6wA//Ud8gH3N7vq5zh8IZ+PjdSOuIk0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}