SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '173ca88142e5a651add824a8fefbfc95d5447ff42cd01bc9df68328d60eda5d5' 
  AND token = 'Axrj4nM2+nTN0rTIllD+xRVuSIfmVSp0/CGI/VThhpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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