SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26ebfe2804af7fba93003377913fde4089dbb5f46c393eedeabd488fae4e984d' 
  AND token = 'SpV7oVvkcHeE+B67qdjgLMcoQ2DfKZeOzfDdpjDU16I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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