SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf0bd86cc79b7dae186ab3ff5439ad3522ffebaacb7430c0c7f71e2e95669cd1' 
  AND token = 'kywb9mRm5DxuLW/rjLYf1RpohiPLCQrQmlQtrBt7G7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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