SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2f72ea80ff7deff4619e30319f061050212348c51beaff3ec4f6a5504637deda' 
  AND token = 'rudrcC0j/OXZnmNRY+ERq5LOpnb58vcXjtP6xrfzKho=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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