SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '78609ff7dcdaf931bdf9f7f968b643a3d025c231c516fdf96ae06dacbdcdceb5' 
  AND token = 'UO5wQwydQht5qsdv210L7xri6xbc2+1vTe9AjydCTDQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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