SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20d1e3641c403735f5cca56f5bbb9c1211766bda8ad3f07282fd19ecfd96a74b' 
  AND token = 'Zq0vB+mQRXLPnguPPRogwxFuExi4ZO+YO57u5vhQBPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}