SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8003a8e3190a7e5eaba002b551a5f0a8f21150bae8de25d60ebd1d4d5f0ed6ef' 
  AND token = 'lxAMnHPKKzfSnCh16BEU7D3t2JtJn4SRSWKf5yxCxdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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