SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '64c4cd55ae94835d9f14f050a50238ad1df004699065219028716fb8112eea11' 
  AND token = '5ODHmxvC4DjSIc1A+ZdOMBNzOFwKG99iLtV8Yhab1q4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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