Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5e74dc1b97d31b32cf0678927719f6240ee86b9a8b90ca45bb344bb693bd6e88' 
  AND token = 'R/8ZILTI5yiTFnJ59CbmRDIokLVtCvVIDeYjQmuaNZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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