SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0486c3e1902837970d7636435665a892025ec77dfc349dfc5706ce6608f6b7c' 
  AND token = 'jYdpLDyJldsfCvW3VZZP9ZDIMOgsY5Ad54VJ2+ZGNGA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00052

JSON explain

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