SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '494d02f419e970843c4ae13eaf47bd622e3bac9cbb6cf8d938f67ef8207f297b' 
  AND token = '77vYjfcs39vs0vDRB/o+5eKZid5EqmZDVypcmuIg7AA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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