SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ca06214b594be913e07fc1f3dbbdabbdbbb818cc3f419e99fc05146780fbe41' 
  AND token = '0nCFE/MVqwCPDuac2N4r8hHQQb1Pa/MM0vdI/Kk0p1E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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