SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9671867c0466101a26c703b2088fbba17cf0fbd7e03ed4c6a5d587e0632c49c' 
  AND token = 'JroDhC+8BfiVRhdkM8IChjjzcc46wkS2ZoXcXz+ro5Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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