SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f85c502f657ff1c26efc2f1144e3a8066e8e3fe42dd9df8d3a2d1f950bc6b8b7' 
  AND token = 'nZDP9nyXac6jHTQPcXSrDlFFbpqqrSxtYVMH5+AND20=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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