SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff5ba0053080515d46141a37f19ae521881f01f645c835ef495ba59a8e561bb5' 
  AND token = '5pQlS0m4k5OT7dAx1mV+dYpuDNTcR01pOnFoVzISNw8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}