SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a070231dc87d24e92cdc770c54113a1c9b059ddeb3e13be92e8b632b80a738f8' 
  AND token = '+cZ3X14o3/VoimdiZDMrOl4ERzLU8YikpZBqHCcx1CI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00094

JSON explain

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